Necessary preliminary tasks:
NOTE: Extract brake fluid out of expansion tank. Use a suction bottle used exclusively for drawing off brake fluid.
Do not reuse drawn out brake fluid.
Disconnect plug connection (1).
Release retaining screw (2).
Detach expansion tank (3) by pulling vertically upward.
IMPORTANT: Check rubber plugs (1) in brake master cylinder for damage and replace if necessary.
Push the expansion tank vertically onto the master brake cylinder.
BMW X3 Service & Repair Manual > Disc wheels (rims): Initializing run flat indicator (rpa)
NOTE:
Checking the tire pressure is based on speed monitoring of the wheels in
relation to each other. A tire puncture is detected and signalled by way of a
deviation in specific speed ratios.
The four tires mounted on the vehicle are monitored while the vehicle is
driving.
Initialization ...